программа для тестирования регулярных выражений, совместимых с Perl (a program for testing Perl-compatible regular expressions.)
NON-PRINTING CHARACTERS
When pcretest is outputting text in the compiled version of a
pattern, bytes other than 32-126 are always treated as non-
printing characters are are therefore shown as hex escapes.
When pcretest is outputting text that is a matched part of a
subject string, it behaves in the same way, unless a different
locale has been set for the pattern (using the /L modifier). In
this case, the isprint() function to distinguish printing and
non-printing characters.
